A so-called compact foil intermediate layer comprises a single foil positioned in a joint between adjoining machine parts which are subject to chafing or friction or fretting corrosion. The foil prevents a direct surface contact between neighboring parts which are subject to oscillations and/or vibrations. However, the material of the single foil is subjected, in addition to changing compression loads, to increased shearing forces due to the effects of the fretting corrosion. Therefore, the single foil intermediate layer has a relatively short working lifetime due to the resultant fretting corrosion and microcrack formation so that the foil must be replaced frequently. Another method of protecting adjoining machine parts against fretting corrosion is disclosed in the German Patent Publication No. (DE-PS) 3,133,158, wherein an independent foil intermediate layer is not used. Rather, a material is introduced into the joint between the machine parts by a method as disclosed in No. (DE-PS) 3,133,158 so that the material forms an intermediate layer which adheres to the surfaces of the parts to be protected. The intermediate layer thus forms a mechanical unit with both part surfaces so that disadvantageously the parts cannot be disassembled without breaking and destroying the formed intermediate layer. A further disadvantage of such an adhering intermediate layer is that microcracks are caused in the intermediate layer due to high shear forces during vibrational loading. Further, due to the mechanical adhesion or bonding the microcracks can propagate into the material of the machine parts to be protected. Thus, the intermediate layer fails to serve its important function and the working lifetime of the machine parts to be joined is reduced.
German Patent Publication No. (DE-PS) 3,236,376 discloses a further development of such an adhering protective layer or coating, whereby the surfaces of the machine parts to be joined are separately coated with a protective coating of, for example, copper, silver, or aluminum. A disadvantage of these protective coatings is also the propagation of microcracks caused by fretting corrosion into the parts themselves.